Serie A began on time this year, with the new collective contract agreed this month between the league and the players' association ensuring that there would be no repeat of last season's strike action. Milan's supporters may wish it hadn't.

A one-week delay may not have improved their team's performance, but at least by then they would have known exactly how to feel about it. "31 August, we are waiting patiently," read one of the banners on display at San Siro as the Rossoneri opened their campaign at home to Sampdoria, yet by full time such equanimity was being tested. Their newly promoted opponents had produced the shock of the weekend by snatching a 1-0 victory, Milan unable to find a response to Andrea Costa's second-half header.

If the lack of a truly furious reaction from the home support at the end suggested they were indeed willing to await the close of the transfer window before passing judgment, the truth was that many fans had already voted with their feet. An attendance of just 36,288 was Milan's lowest for a home opener this millennium. Although season-ticket sales are not yet closed, the club have thus far shifted almost 6,000 fewer than in their previous worst year under Silvio Berlusconi's ownership. Those figures have to be viewed in the context of a transfer campaign of unprecedented austerity.

Milan have survived the loss of players equivalent to Thiago Silva or Zlatan Ibrahimovic in the past, but never before under Berlusconi have they allowed two such talents to leave at once without at least the promise of significant reinvestment. Instead this was a summer in which Alessandro Nesta, Antonio Cassano, Clarence Seedorf, Mark van Bommel and Gennaro Gattuso were also ushered out the door. In their place came only players who were available at bargain basement prices. Francesco Acerbi and Cristián Zapata may prove useful but they are hardly signings to set the pulse racing. Riccardo Montolivo's stock, too, had fallen during a difficult last year with Fiorentina.

"I endorsed all the club's transfer decisions," claimed Massimiliano Allegri after the game, insisting he would have walked away if that was not the case, yet such words cannot disguise the disharmony between the manager and his club's board. Last week a deal to sign the Brazilian forward Ze Eduardo from Genoa fell through amid reports Allegri had threatened to resign if the vice-president Adriano Galliani went through with the purchase. Allegri made it plain that he does expect new players to arrive before the transfer window closes, with Kaká – despite Galliani's protestations about the improbability of reaching agreement with Real Madrid – still widely expected to find his way back to the club.

Sunday's performance, though, raised fresh doubts over the manager's capacity to get the best of the players he does have. Depleted they may be but with players such as Kevin-Prince Boateng, Robinho and indeed Montolivo available, Milan ought still to have been able to cope with a team who finished sixth in Serie B last season. Instead the home team were ponderous through the first half and panicked in the second – eventually succeeding in hitting the woodwork twice and having another effort cleared off the line, yet never conveying the impression of a team with any form of coherent gameplan.

That is to Sampdoria's credit as well, of course. Where Milan were disjointed, Ciro Ferrara's side were a model of patient discipline, retaining their shape rigorously even if that meant passing up opportunities to test their opponents' uncertain backline. Samp got their reward with a goal from a corner, albeit they still required a bit of luck and some fine goalkeeping from Sergio Romero to get them across the line.

Such a mature display could hardly have been expected from such a young group. Sampdoria's starting XI had an average age of 24, and not a single player over the age of 30. Freshly returned to club football after two years in charge of Italy's Under-21 team, Ferrara appears minded to practise what the Italian Football Federation has been preaching to its members in terms of showing faith in youth.

That becomes easier, of course, when the young players available are of such a high calibre. "Not everyone has a midfield like ours," noted Ferrara proudly on Sunday night. "The class of [Andrea] Poli, the boldness of [Pedro] Obiang, the solidity of [Nenad] Krsticic and the personality of [Fernando] Tissone."

Ferrara will only hope that he does not lose any members of that group in the remaining days of the transfer window. Many were surprised that Inter declined to take up the option of signing Poli on a permanent deal after having him on loan last year, and Juventus are understood to be among a group of teams keeping close tabs on his progress.

Milan, then, are not the only club facing up to a nervous five days. But the real fear for Galliani, as he reflects on Sunday's gate receipts, is that anxious fans could eventually become apathetic ones.

Talking points

• Helping Galliani's mood none over the weekend were Antonio Cassano's comments during a lively press conference in which the player implied that the Milan vice-president had made false promises over a new contract. "I didn't mess up at Milan, the players didn't mess up and nor did the manager, but someone higher up than him," said Cassano. "Someone who made promises and didn't keep them … someone who was all smoke and no roast dinner." Galliani rejected the charge, and Milan's supporters made plain their feelings about Cassano with some colourful banners at San Siro. It's safe to assume Fantantonio was not too bothered, though, as he started and provided an assist in Inter's 3-0 win at Pescara.

• Also worth noting from Inter's win: another goal from Diego Milito. The striker's 21 strikes so far in 2012 (in all competitions) place him third among players in Europe's top leagues – behind only Leo Messi and Cristiano Ronaldo.

• Where Milan's supporters were staying away, Zdenek Zeman's return to the Roma bench prompted a near sell-out at the Stadio Olimpico for their game against Catania. The crowd would certainly get their money's worth – Roma throwing themselves forwards as Zeman's sides always do and getting caught out at the back as his sides often are. Twice Roma fell behind – though another officiating crew might have disallowed both Catania goals for offside, but both times they responded with goals of supreme quality. The pick of the bunch, and probably the pick of the weekend in Serie A was an overhead kick from Pablo Daniel Osvaldo – every bit as good as the one he had wrongly disallowed last year.

• A day earlier, Juventus had seemed to cope just fine without their suspended coach, Antonio Conte, during a 2-0 win over Parma, though here too there was fresh controversy. Did Andrea Pirlo's free-kick really cross the line for the second goal? Even after repeat viewings, it's almost impossible to tell. So instead just be grateful that Arturo Vidal missed his first-half penalty for the champions – since Stephan Lichtsteiner ought to have been flagged for offside immediately before winning it.

• Also on Saturday, Fiorentina confirmed impressions of a team moving in the right direction once more under Vincenzo Montella by recovering from a goal down to beat Udinese. "[Stevan Jovetic] can easily score 20 this season," said Montella of the Montenegrin forward, responsible for both his team's goals. Fiorentina fans will only hope that he does so for them, amid suggestions that Juve could yet make a late play for his services.